The nutritional content of sea veg
Sea vegetables are products we know are healthy and that we should be eating regularly. But I get a lot of people asking what is so special about them, and what should they do with them. In this post I’ll be covering the nutritional content of sea veg. Future posts will cover the health side and cooking and using. To keep the length manageable I’m not covering why any of these nutrients are useful, again this will have to be a whole series.
All our sea veg comes from off the Galician coast, in Spain. I know the Japanese assure us that their waters have not been contaminated by the “problem” at the nuclear plant a couple of years ago. But I would rather play save. A Spanish source also reduces food miles.
Sea veg are rich sources of a very wide range of both the bulk and trace minerals we need for health.
Calcium – milk contains 120mg of Calcium per 100g, wakame contains 1380mg. All other sea veg also contain high levels of Calcium Calcium absorption is dependent on the ratio of Calcium to Phosphorous. Milk has a far from ideal ratio, all sea veg have a much better ratio.
Phosphorous – sea veg have high levels of this mineral, again in a good ratio with calcium.
Magnesium – another mineral whose absorption is dependent on its ratio with Calcium. Sea veg scores very favourably.
Sodium – one might expect sea veg to be too high in salt. But an important factor with salt is the sodium to potassium ratio, which is very good in all sea veg. The sodium in sea veg means less salt needs to be added when cooking.
Potassium – sea veg contain high levels of potassium, dulse is the best source.
Iron – sea veg contain good levels, in a easy to absorb form. Dulse contains 50mg of iron in every 100g, compared with 6.9mg in lentils and 2.7mg in eggs.
Iodine – all sea veg contain far higher levels than land plants. Best sources are kombu, wakame and nori.
Cobalt – best source is kombu, but all sea veg are rich in cobalt.
Manganese – dulse and nori are particularly useful.
Selenium – many soils are very deficient in Selenium. Nori and wakame are the best sources.
All sea veg are also good sources of sulphur, zinc, silicon and copper.
Sea veg are a rich source of protein. Wakame contains 22.7% protein, compared with soya 35% and almonds 19%. They also contain all 8 essential amino acids, very rarely found together in the plant kingdom.
Sea veg are low in fat, usually less than 3% of their weight. The fat they do contain is high in unsaturates, particularly linoleic acid, an Omega 3 fat vital for health which many people are short of.
As with minerals, sea veg are a valuable source of a wide range of vitamins.
A – nori contains 3.6mg of vitamin A precursor per 100g compared with 1.1mg in carrots, the best land veg. The body only converts as much as this precursor to vitamin A as it needs, so it is impossible to overdose. Retinal, the precursor in animal products, is all converted which can lead to excess.
B – sea veg contain good quantities of B1, B2, B3 and B6. Eating them rare is best for these vitamins, so wakame and dulse are recommended.
B12 – this is a problem for many vegans. Sea veg does not contain B12, but it is synthesised by bacteria associated with them. It is claimed that sea veg are, therefore, one of the few plant sources of B12. Scientific papers show this. But, I can find no papers written by anyone unconnected with the industry in some way. I would urge caution till more independent research has been carried out.
C – sea veg are reasonable sources, helped by their high level of iron, which helps absorption of vitamin C. Cooking removes vitamin C, 25 minutes in water halves the vitamin C content. So best to eat raw, or use the cooking water for gravy or soup.
D – sea veg has no vitamin D, but does contain algosterol, a precursor.
E – sea veg contains about the same amount as olive oil, much higher levels than in whole cereals.
There are basically two types of fibre, insoluble and soluble. Insoluble fibre, found in wheat, helps prevent constipation by encouraging peristalsis. Sea veg are not a particularly useful source.
The soluble fibre found in sea veg slows the absorption of food from the digestive tract. It also binds water and fats to itself. This fibre profile has a number of health benefits, However, this is a large area which needs to be covered in the health aspects of sea veg blog.
Sea veg are an excellent source of a very wide range of nutrients. Some of the figures I’ve quoted are very impressive indeed. However, we need to bear in mind that someone is unlikely to have such a large portion of wakame than of, for example, carrots.
I think the healthy approach is to see them as somewhere between a vegetable and a condiment, eating small portions at least a couple of times a week. All have an excellent nutrient profile, so ringing the changes seems sensible, as one would with land vegetables.